Shear pin drive for stokers



Jam.` 1'7, 1939.4 G, M. FiELTz SHEAR PIN DRiIVE FOR STOKERS 'Filed Feb. l5, 1938 Patented Jan.4 7, 1939 i suma rnv narvn Foa erom-:ns

Gordon M. Peltl, Portland, Oreg., r to land, 0M.

Manufacturing Company, Port- Appnmm Fem-uw 1s, lass, sem 110.190.604

4 am. (el. x4-za) 'I'hls invention relates generally to coal burning stakers, and particularly to a shear pin driving connection therefor.

The main object ofthis invention is the provision of an exceedingly simple and efficient' form of shear pin driving connection which will be `simple to manufacture, sturdy inconstruction and easyto restore to a working condition after a pin has been sleared.

The second object is to facilitate the insertion 'of a shear pin regardless of-the relative circumferential positions in which the parts have .stopped or the relative longitudinal positions of the pin holes.

The third object is to render unnecessary, a realignment of the parts prior to the insertion of the shear v-pin.

These, and other objects', will become more apfparent from the specification following as illus-y trated in the accompanying drawing, iii which:

Fig. l is a fragmentary side elevation of a gear case showing a portion thereof as well as the worm housing broken away in cross-section.

Fig. 2 is a section taken along the`line 2-2 in Iiilg.i 1.

Fig. v3 is a perspective view showing the engaging position ofthe driving unit.

F'ig. 4 is a fragmentary perspective view of a- 4 mounted on the shaft Il wose'squared end II projects-into the end of the fuel worm i2. 'I'he gear i3 is provided with a cylindrical hub Il from whose end Il projects the vjawy Il whose faces I! are substantially radial.

Also mounted on the shaft Iljis a driving collar which is provided with a lug 2l whose faces 22 are substantially radial. 'Ihe faces il are preferably less than ninety degrees apart; The same is` true of the faces 22.

Through the collar 2l extends a shear pin hole 23 which is normally in register with a hole 24 in the shaft il. 111e holes 23 and .24 normally contain the shear pin 2i which is made of a size and mam-a1 humble for the mil-pose. n is l aanbietnpmmeaaqumaheadzlon'theemof the shaft Il forl thenormal operation thereof;

A shear pin cap 21 encloses thecollar 20 and is' If'a pin 25 is sheared due to an overload on the worm I2, it follows that the gear I2 can no longer drive the worm I2 since the gear I3 is now free to turn upon the shaft- Il. It therefore becomes necessary to replace the sheared pin -25 with a new one. It can be seen`that the sheared Iparts can easily be removed by slipping the collar 20 off of the end of the shaft Il and then driving out the sheared pin parts. I'he collar 2l is then replaced on the shaft Il and rotated as well as moved longitudinally until the holes 23 and 2l are in register. The new pin 25 is then inserted and the snap ring is moved into place.

It can be seen by an inspection of Fig. 2 of the drawing that the holes/22 and 24 may be brought into register from any position in which the parts are stopped owing'to the fact that the possible relative movement between the members I8 and 2l is greater than 180.

While I have shown the device employing a;

singlelug 2| cooperating with a single jaw I8,

- it is obvious that'two or more of these could be employed if a corresponding number of. holes 2l are provided in order to permit the vinsertion of the pin 25 in any relative position whichl may exist between the shaft Il andthe collar 2l.

It is, of course, a matter of common knowledge lthat shear pin drives have long been in use.` It

is therefore not my intention to cover such deV vices broadly, but I do intend to cover all such forms and modications thereof which fall fairly within the appended claims.

I claim: y

l. A drive of the class described having in combination a driven shaft. a driving gear mounted on said shaft, va driving collar secured to said driven shaft by means of a shear pin, a clutch between said driving collar and gear character ized by having more than of lost motion bei tween the jaws thereof.

2. .4 device of the class described consisting nr a driven shaft, a'drive gearmounted on said shaft, said drive gear having a laterally projecting jaw,

a driving collar secured to said driven shaft by means of a shear pin, said driving collar also having a projecting jaw adapted to engage the jaw 

